An image forming apparatus refers to an apparatus that forms an image on a print medium according to an input signal. Image forming apparatuses can be printers, copiers, facsimiles and multifunctional devices that integrate one or more functions of aforementioned.
An electro-photographic image forming apparatus is a type of image forming apparatus that scans a light beam corresponding to image information to a photosensitive member charged to a predetermined electrical potential to form an electrostatic latent image on the surface of the photosensitive member. A developer can be supplied to the electrostatic latent image to form a visible image. The visible image formed on the photosensitive member can be transferred directly to a print medium or can be transferred indirectly to the print medium via an intermediary transfer unit. The visible image transferred to the print medium can be fixed to the print medium by heat and pressure applied to the print medium while passing through a fusing device including a heating device and a pressing device.
When the width of the heater in the fusing device does not correspond to the width of the print medium, some issues could arise including the deterioration of the fusing capability, damage to the print medium and/or damage to the fusing device, for example.